Berlin Astronomy - Snippets
A.A. Michelson
A notable event occured in 1881, when Michelson attempted his first reliable experiment to detect the Earth's motion with respect to the ether, in the cellar under the eastern dome. His continual lack of success in detecting any motion in this and later experiments in America led eventually to the overthrow of the ether theory - and towards the Special Theory of Relativity.
Stellar Magnitudes
Starting from the second half of the 19th century, stellar magnitudes were revised to correct the crude methods that had existed up to then. A precise investigation at Potsdam resulted in the Potsdamer Photometrische Durchmusterung by G. Müller and P.Kempf. In full - 'Photometric Catalog of the Northern Sky, Containing the Magnitudes and Colors of all Stars of the B.D. to Magnitude 7.5' (Photometrische Durchmusterung des Nördlichen Himmels, enthaltend die Grössen und Farben aller Sterne der B.D. bis zur Grösse 7.5)
ε Aurigae
H. Ludendorff determined an orbital period of 27.1 years for the eclipsing binary ε Aurigae, soon after an eclipse of 1900-1902.